Here's a cool tool that brings something fresh to the world of viral video (for a good month or two, at least ;-) - Personiva. Personiva allows for the creation of branded content that can be personalized by the viewer, for the viewer. For example you might upload a photo of you, Personiva integrates it inside a specially-made commercial, and you get to watch a TV ad featuring you.

While the experience is certainly new, its current application doesn't strike me as something that will last (the Levi's example on their site wasn't all that impressive), but I salute the idea. I do hope they find a way to push this a lot further.